The efficacy chemopreventive agents to inhibit angiogenesis will be tested in the chorioallantoic membrane (CAM) assay, wherein the inhibition of new vessel formation is computed by the intrafocal microvessel density (IFMD) and by the circumfocal microvessel number (CFMN). The system compares 3 types of angiogenesis evoking cells, including human glioblastoma MF, human tumor cells with defined genetic elements, and syrian hamster embryo cells transduced with v-Ha-ras and v-myc as a positive control. Additional endpoints include VEGF, Integrins, and apoptosis induction of vascular endothelial cells.